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Interim Recommendation issued to: Beech Aircraft Corp

Recommendation details
Output No: IR19990090
Date issued: 28 July 1999
Safety action status:
Background: Why this Interim Recommendation was developed

Output text

The Bureau of Air Safety Investigation recommends that Raytheon Aircraft examine and implement methods of preventing incorrect passenger oxygen system mask container door fitment as installed in Beech King Air B200 series aircraft, and other Raytheon aircraft similarly equipped.

As a result of the investigation into this safety deficiency, the Bureau simultaneously issues the following interim recommendations:

IR19990088

The Bureau of Air Safety Investigation recommends that Raytheon Aircraft issue a directive for an immediate check of the fitment of passenger oxygen system mask container doors on all Beech King Air B200 aircraft, and all other Raytheon aircraft similarly equipped.

IR19990084

The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority issue a directive for an immediate check of the fitment of passenger oxygen system mask container doors on all Australian Beech King Air B200 aircraft, and all other aircraft similarly equipped.

IR19990089

The Bureau of Air Safety Investigation recommends that the Federal Aviation Administration issue a directive for an immediate check of the fitment of passenger oxygen system mask container doors on all Beech King Air B200 aircraft, and all other aircraft similarly equipped.

Initial response
Date issued: 11 January 2000
Response from: Beech Aircraft Corp
Action status: Monitor
Response text:

RAC will make a production design change to the B200 oxygen mask containers to provide a method of preventing the doors from being installed incorrectly. RAC will make available through spares, and announce via a Recommended Service Bulletin, the same change to all delivered airplanes. The production design change is tentatively scheduled to be completed by the end of the second quarter of 2000.

RAC has investigated to determine whether the condition referenced in the Interim Recommendation might exist in other Raytheon King Air model airplanes:

* The Model C90A does not have an auto-deploy or drop-down system. It is totally passenger operated (i.e., the passenger opens the door and plugs in the mask).
* The Model B300 is an auto-deploy system made by Puritan Bennett. The lid is permanently attached to the box with two metal lanyards. The lanyards are not long enough to allow the door to be rotated and installed improperly.
* Model 200 serials BB-1 through BB-54 (excluded from the applicability of the B200 system) use the same system as the Model C90A.
* The Model F90 has an oxygen system design similar to the B200. The Interim Recommendation therefore applies to the Model F90 as well. RAC will address the F90 in all corrective actions.
* The Model 100 has an oxygen system design similar to the C90A. It does not have an auto-deploy or drop-down system. It is totally passenger operated (i.e., the passenger opens the door and plugs

In addition to the King Air Models, RAC has investigated to determine whether the condition referenced in the Interim Recommendation might exist in other Raytheon model airplanes. The investigation revealed that the condition does not exist. Specifically:

* The Commuter Airplane Series (Model 1900, 1900C, and 1900D) oxygen box door design does not allow the door to be installed backwards or in any other manner which would prevent the plunger from releasing the door.
* The Beechjet Airplane Series (Model 400, 400A, 4001) design does not permit the oxygen doors to be installed backwards.
* The Starship (Model 2000) does not have the same cover design and cannot be installed backwards. The hinge tabs are on one side, and the plunger interface is on the other. The plunger interface is part of the door. There are no slots for the hinge tabs on the other side of the box, so that the door cannot be installed 180 degrees out. Also, the plunger cannot be inserted into the valve body if the door is backwards.

The Hawker Airplane Series design does not permit the oxygen doors to be installed backwards.

This information has also been supplied to the U.S. FAA.

(* Letter to FAA:)

RAC has reviewed the Safety Recommendations submitted in FAA's letter dated September 16, 1999, regarding the oxygen mask container and its door. RAC agrees that the door can be installed incorrectly, causing the masks not to deploy as intended.

Design applicability and description
Models B200, 300, and 200 (except BB-1 thru BB-54) use an auto-deploy system from Puritan Bennett. Puritan Bennett provides the box with plungers and masks. RAC provides the lids and plastic lanyards that are attached to the RAC escutcheon.

Recommendation 99.301:
The Bureau of Air Safety Investigation recommends that the Federal Aviation Administration issue a directive for an immediate check of the fitment of passenger oxygen system mask container doors on all Beech King Air B200 aircraft and all other aircraft similarly equipped.

RAC Response:
RAC does not have an objection to FAA issuing an AD on this subject matter. However, RAC has issued sufficient information on the Model 200 Series regarding repetitive inspections and functional tests on the system that should be adequate to ensure their proper operation (copies of the Maintenance Manual pages are enclosed).

Specifically, the Model 200 Maintenance Manual requires that an oxygen system functional test be performed at Phase 1 and Phase 3 (initially at 200 and 600 hours, and every 800 hours thereafter for both phases.) During the oxygen system test (Model 200 Series Maintenance Manual, in Chapter 35-00-00, Page 217, paragraph d) the operator is required to ensure that the doors on the mask containers open and the masks drop out.

Additionally, the Model 200 Series Maintenance Manual cautions operators that the oxygen "Container door can be positioned 180' off. If this happens, the plunger cannot push the door open when activated." This Caution note appears in Chapter 35-00-00, Pages 215 and 216, in Step 1 (Page 215) and Step i (Page 216).

The Model 300 Series Maintenance Manual requires that an oxygen mask pressure test be performed at Phase 1 and Phase 3 (initially at 200 and 600 hours, and every 800 hours thereafter for both phases.) During the oxygen mask pressure test (Model 300 Series Maintenance Manual, in Chapter 35-00-00, Page 6, paragraph f) the operator is required to ensure that the doors on the mask containers open and the masks drop out. This manual, however, does not provide a Caution note regarding improper door installation that might prevent the door from opening when activated. Therefore, the Model 300 Series Maintenance Manual will be revised at the next scheduled revision to add the caution note and the similar safety information provided in the 200 Series Maintenance Manual.

Recommendation 99.302:
The Bureau of Air Safety Investigation recommends that Raytheon Aircraft issue a directive for an immediate check of the fitment of passenger oxygen system mask container doors on all Beech King Air B200 aircraft and all other Raytheon air-craft similarly equipped.

RAC Response:
RAC has published an article regarding this subject in a King Air Model Comununique. The Communique is being mailed this month. Additionally, RAC is preparing a Safety Communique against all airplanes with auto-deploy oxygen masks to ensure that all operators are aware of the importance of properly installing the doors on the oxygen mask boxes.

Recommendation 99.303:
The Bureau of Air Safety Investigation recommends that Raytheon Aircraft examine and implement methods of preventing incorrect passenger oxygen system mask container door fitment as installed in Beech King Air B200 series aircraft and all other Raytheon aircraft similarly.

RAC Response:
Raytheon Aircraft will make a production design change to the B200 oxygen mask containers to provide a method of preventing the doors from being installed incorrectly. RAC will make available through spares (Recommended Service Bulletin), the same change to all delivered airplanes. The production design chance is tentatively scheduled to be completed by the end of the second quarter of 2000.

Applicability on other Models
RAC has investigated to see if the condition referenced in the Safety Recommendation may exist in other Raytheon King Air Model Airplanes:
* The Model C90A does not have an auto-deploy or drop-down system. It is totally passenger operated (the passenger opens the door and plugs in the mask).
* The Model B300 is an auto-deploy system made by Puritan Bennett. The lid is permanently attached to the box with 2 metal lanyards.
* Serials BB-1 through BB-54 (excluded from the applicability of the B200 system) use the same system as the Model C90A.
* Model F90: RAC is still investigating and will provide a complete response to FAA by November 30, 1999.
* Model 100: RAC is still investigating and will provide a complete response to FAA by November 30, 1999.

In addition to the King Air Models, RAC has investigated to see if the condition referenced in the Safety Recommendation may exist in other Raytheon Model Airplanes. The investigation revealed that the condition does not exist. Specifically:
* The Commuter Airplane Series (Model 1900, 1900C and 1900D) oxygen box door design does not allow the door to be installed backwards or in any other manner which would prevent the plunger from releasing the door.
* The Beechjet Airplane Series (Model 400, 400A, 40OT) design does not permit the oxygen doors to be installed back-wards.
* The Starship (Model 2000) does not have the same cover design and cannot be installed backwards. The hinge tabs are on one side and the plunger interface is on the other and is part of the door. There are not slots for the hinge tabs on the other side of the box so that the door cannot be installed 180 degrees out. Also, the plunger cannot be inserted into the valve body.
* The Hawker Airplane Series design does not permit the oxygen doors to be installed backwards.

ATSB response:

The following email was sent to Raytheon Aircraft Corporation on 29 May 2002:

To enable the ATSB to finalise our report on the incident, could you please provide details of the production design changes, including any IPC references, that have been made by Raytheon to prevent the doors from being installed incorrectly.

 
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Last update 01 April 2011